Servier has acquired KER-0193 from Kaerus Bioscience, gaining a potential treatment for Fragile X syndrome, a rare genetic condition that is the most common single-gene cause of autism spectrum disorder. The deal strengthens Servier’s neurology pipeline as part of its 2030 strategy.

The French pharmaceutical group said the acquisition of KER-0193 is its first neurology asset deal, adding to a pipeline aimed at rare diseases with high unmet medical need. Kaerus Bioscience, a UK company created by Medicxi in 2016, discovered and developed the small molecule and completed a Phase 1 study earlier this year. The trial showed the candidate was safe and well tolerated, with favourable pharmacokinetics.

Claude Bertrand, executive vice-president of research and development at Servier, said: “KER-0193 is Servier’s first asset acquisition in neurology and so marks a significant milestone in our 2030 strategy, reinforcing our long-term commitment to establishing a leading neurology franchise focused on rare diseases.” He added that advancing the candidate reflects the company’s determination to build “a differentiated pipeline of innovative therapies for patients with underserved needs.”

KER-0193 has already been granted Orphan Drug Designation and Rare Pediatric Disease Designation by the US Food and Drug Administration. Servier said it plans to launch a Phase 2 trial in patients with Fragile X syndrome in 2026 in both America and Europe.

Robert Ring, chief executive officer of Kaerus Bioscience, said: “We strongly believe in the therapeutic potential of KER-0193 in Fragile X syndrome. Servier’s firm commitment to neurology and global capabilities make it the ideal partner to further develop KER-0193 for patients worldwide.”

The terms of the agreement include an upfront payment to Kaerus Bioscience, with further development and commercial milestones. Servier said the total value of the deal could reach $450 million.

KER-0193 is an orally bioavailable small molecule that modulates BK channels linked to Fragile X syndrome. Preclinical studies have shown therapeutic-like effects across behavioural, sensory, and cognitive measures relevant to the condition.

Michèle Ollier, venture partner and co-founder of Medicxi, said the deal validates the strategy behind Kaerus: “Kaerus Bioscience was created by Medicxi to advance a clear product vision to develop a potential first-in-disease therapy for Fragile X syndrome. We are extremely proud of the scientific progress achieved by the Kaerus team, and are excited that this deal with Servier will accelerate the development of KER-0193.”

Fragile X syndrome affects around 1 in 7,000 males and 1 in 11,000 females worldwide. It is the most common genetic cause of intellectual disability and accounts for about 1% of autism and intellectual disability cases globally. No approved treatments currently exist.